Complete Properties of Electrons Demonstration Apparatus
by United Scientific

Based on a 75mm flat screen CRT (cathode ray tube), the entire unit is held within a compact metal case with a removable lid. It includes all the accessories required to explore electrostatic deflection, focusing, and electron behavior in transverse and axial magnetic fields. To ensure safety and reliability, the circuitry for both the power supply and the measuring devices are entirely enclosed beneath the work surface of the unit.

It features multiple multi-turn potentiometers to adjust and introduce variables into the experiements, and has 3 LED meter displays to easily help with obtaining precise numbers. The operator’s manual comes complete with multiple experiment descriptions, as well as an explanation into their backgrounds and procedures. This includes, but is not limited to determining the e/m using the focusing effect of an electron beam as it spirals around an axial magnetic field.

The CRT itself is a 14-pin tube, approximately 240mm in length with a 75mm diameter round screen at one end, with a separate transparent screen included for use in taking quantitative measurements. Operating on 900-1450V, the tube also includes electrodes for electrostatic focusing and deflection in both horizontal and vertical directions.

Two 530-turn magnetic field coils of 30mm mean diameter for the transverse field plugs directly into the sockets located in the base, while a 1300-turn solenoid with a 95mm mean diameter for the axial field fits directly over the CRT, connecting to the base via patch (banana) cords.

Coarse and fine adjustments can be made using the control system to operate the tube, while the focusing and acceleration potentials can be set and monitored separately, as can the electrostatic deflection. Yet another section allows power to be transfered to the transverse and axial magnetic field coils.